(1S,2S,3R,4S,5S)-5-amino-1-(hydroxymethyl)cyclohexane-1,2,3,4-tetrol

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a stirred solution of valiolamine (80 mg, 0.414 mmol), in 96% aq. methanol (5.2 mL) was added 3,5-di-t-butyl-1,2-benzoquinone (92 mg, 0.418 mmol) dissolved in methanol (2 mL) at room temperature. After stirring for 90 min, water (1 mL) was added, the pH lowered to 5.0 (pH paper control) with an aqueous solution of oxalic acid, and the mixture shaken vigorously for 45 min. Subsequently, the pH was adjusted to 8 with ammonium hydroxide. The mixture was diluted with water (80 mL) and extracted with chloroform (4×40 mL). The water phase was concentrated to approximately 5 mL in a vacuum and loaded onto an IRA-68 anion exchange column (40 mL, OH- -form). Elution with water gave a fraction containing the product. This solution was concentrated to 1 mL and further purified by chromatography on a weak cation exchanger (Wk-100, 40 mL, NH4+ -form, mobile phase: water) to give pure valiolone (42 mg, 0.219 mmol, 53% yield). 1H NMR (300 MHz, D2O), δ(ppm): 2.39 (d, 1H, J=14.6 Hz, HCH--C=O); 2.79 (d, 1H, J=14.6 Hz, HCH--C=O); 3.3 (d, 1H, J=11.5 Hz, HCH--C--OH); 3.62 (d, 1H, J=11.3 Hz, HCH--C--OH); 3.63 (t, 1H, J=9.5 Hz, HC-3); 3.84 (d, 1H, J=9.4 Hz, HC-4) and 4.19 (d, 1H, J=9.7 Hz, Hc-2). 13C NMR (75 MHz, D2O), δ (ppm): 45.45, 64.37, 72.91, 75.79, 76.01, 78.62 and 209.43. the mixture shaken vigorously for 45 min extracted with chloroform (4×40 mL) The water phase was concentrated to approximately 5 mL in a vacuum Elution with water gave a fraction containing the product This solution was concentrated to 1 mL further purified by chromatography on a weak cation exchanger (Wk-100, 40 mL, NH4+ -form, mobile phase: water)

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: An aqueous solution (30 mL) of validamycin G (106 mg) was submitted to catalytic reduction at room temperature under atmospheric pressure in the presence of platinum oxide (10 mg). The catalyst was removed by filtration and the filtrate was adsorbed onto a column of Amberlite CG-50 (NH4+ form, 30 mL) followed by washing with water and then elution with 0.5N aqueous ammonia. The eluate was concentrated to dryness under reduced pressure, and the residue was dissolved in 1N sulfuric acid (20 mL) and hydrolyzed at 80° C. for 10 hours. The reaction mixture was neutralized with barium hydroxide and the supernatant obtained by centrifugation was concentrated under reduced pressure. The concentrate was adsorbed onto a column of Amberlite CG-50 (ammonium form, 20 mL) followed by washing with water and then elution with 0.5N aqueous ammonia. The eluate was concentrated under reduced pressure and submitted to column chromatography on Dowex 1×2 (OH- form, 100 mL) followed by elution with water. The eluate fractions were concentrated under reduced pressure and then freeze-dried, to give a white powder of valiolamine (11 mg). The catalyst was removed by filtration by washing with water elution with 0.5N aqueous ammonia The eluate was concentrated to dryness under reduced pressure the residue was dissolved in 1N sulfuric acid (20 mL) and hydrolyzed at 80° C. for 10 hours the supernatant obtained by centrifugation was concentrated under reduced pressure by washing with water elution with 0.5N aqueous ammonia The eluate was concentrated under reduced pressure followed by elution with water The eluate fractions were concentrated under reduced pressure freeze-dried

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: An aqueous solution (50 mL) of validoxylamine G (420 mg) was submitted to catalytic reduction at room temperature under atmospheric pressure in the presence of platinum oxide (20 mg). The catalyst was removed by filtration, and the filtrate was adsorbed onto a column of Amberlite CG-50 (NH4- form, 50 mL) followed by washing with water and then elution with 0.5N aqueous ammonia (200 mL). The eluate was concentrated under reduced pressure, and submitted to column chromatography on Dowex 1×2 (OH- form, 100 mL) and eluted with water. The eluate fractions (120-200 mL) were concentrated to dryness under reduced pressure, to give white powders of valiolamine (60 mg). The catalyst was removed by filtration by washing with water elution with 0.5N aqueous ammonia (200 mL) The eluate was concentrated under reduced pressure eluted with water The eluate fractions (120-200 mL) were concentrated to dryness under reduced pressure

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: Validoxylamine G (100 mg) was dissolved in 0.05 M phosphate buffer (pH 7.0) (20 mL) and wet cells of Flavobacterium saccharophilum IFO 13984 (about 2 g) were added to the solution, followed by incubation at 27° C. for 24 hours with stirring. The reaction mixture was centrifuged for removal of cells, and the supernatant was adsorbed onto a column (50 mL) of Amberlite IRC-50 (NH4+ form, manufactured by Rohm & Haas Co.), followed by washing with water and elution aqueous ammonia. The eluate was concentrated to dryness under reduced pressure, and the residue was adsorbed again onto a column (50 mL) of Amberlite IRC-50 (NH4+ form) and eluted with 0.1N aqueous ammonia. In succession to the fractions containing valienamine (eluate fractions 120-140 mL), the fractions containing valiolamine were eluted (eluate fractions 340-430 mL). The fractions containing valiolamine were concentrated to dryness under reduced pressure, and the residue was submitted to column chromatography on Dowex 1× 2 (OH- form, manufactured by Dow Chemicals Co.; 2 mL) followed by concentration of the eluate to dryness under reduced pressure, to give white powders of valiolamine (35 mg). The reaction mixture was centrifuged for removal of cells by washing with water and elution aqueous ammonia The eluate was concentrated to dryness under reduced pressure eluted with 0.1N aqueous ammonia In succession to the fractions containing valienamine (eluate fractions 120-140 mL) the fractions containing valiolamine were eluted (eluate fractions 340-430 mL) The fractions containing valiolamine were concentrated to dryness under reduced pressure